Defendant said he was protecting his family when he shot man

Grady Dwayne Duncan got an eerie feeling when a dark pickup pulled into his driveway unannounced the afternoon of May 21, 2011.

The about 30-acre remote property in the 7400 block of San Antonio River Road where he and his wife were painting their home had only one access point, a locked gate that only a handful of people knew the code for.

He knew the driver of the truck probably scaled the gate to reach his doorstep. And he knew the man inside was probably not too happy with him.

"Hey, what's going on?" Duncan asked as he cautiously approached the man he described as a volatile Forrest Marks, whom he'd met months prior at the Coleto Baptist Church.

"Nothing," the mellowed-out Marks reportedly replied. "I was just in the neighborhood. ... Did you hear about my wife?"

Duncan, 38, is charged with murder by shooting Marks with a .40-caliber Smith & Wesson handgun a few hours after his arrival.

Duncan said during his trial Monday that he was defending his wife and 11-year-old son after Marks became irate, probably because he had just learned his wife was cheating on him with another man, Duncan's brother-in-law, whom she'd run away to Louisiana with.

"I told him, 'That had nothing to do with me.' ... He didn't seem too upset," Duncan said of their initial visit.

The mood shifted after Marks and another man, Cecil Harris, returned from buying beer. Duncan was playing drums in his shed when he heard someone shouting. When he came outside, he found Marks sitting with Duncan's wife and another friend at a small ceramic tile table in the front yard that he was banging with his fists.

"He just stops and says, 'I'm going to kill you and your son,'" Duncan said.

Duncan shouted for them to go into the house. He then went to his truck and retrieved the Smith & Wesson. Brandishing it, he told Marks to leave, firing one shot into the ground to get his point across.

"The bullet going off, it didn't even phase him," Duncan said, crying during some points of his testimony. "He crouched down like he was about to run a 100-yard dash."

And Marks was fishing for something in his jean shorts' pockets then - whether it was for his keys or for a Glock he'd showed off to the family before on one of his three visits there during happier times, Duncan didn't know. He didn't wait to find out, either, especially after a Goliad Sheriff's deputy and Marks' father, Travis Marks, had urged him to be cautious because Forrest Marks had a criminal history.

Taking a step back and bumping into the rabbit cages in front of his porch, Duncan said he delivered the fatal shot while standing some 15 feet from Marks. A few seconds had passed.

During cross examination, Eli Garza, assistant criminal district attorney, said those few seconds weren't enough time for Marks to respond, especially after a night of drinking.

"How does that work? How does someone get the impression that they're not welcome if you allow them to sit at your table, drink beer and talk with your wife?" Garza asked.

He said if Duncan believed Marks was so violent, he would've urged his son to stay away instead of come home from a paintball birthday party. He would've told Marks to leave earlier.

Garza said Marks had to go through a lot of obstacles in order to act on his threats, such as the table, various lawn chairs and animal cages and not to mention Duncan himself. He also got Duncan to agree that he was taught as a Marine other methods, such as hand-to-hand combat, to take down a person.

He said if Duncan really believed his family was in danger, he wouldn't have taken any chances.

"You wouldn't have fired a warning shot. You would've hit your target. ... You agree with me, sir, that a threat and an action are two different things?" Garza asked.

Going through countless crime scene photos, Garza pointed out to jurors that the way Duncan claimed the night unfolded didn't match up with the two shell casings investigators found in the yard.

The evidence admitted last week also showed that Marks pawned his Glock years before the shooting occurred. And the Travis County Medical Examiner's Office found a billfold, $39, a can of tobacco and a marijuana pipe inside his clothing.

A witness interview tape was also played for jurors Monday. In that tape, Tony Daniel, a Victoria County Sheriff's Office investigator, is told Duncan made more than just one 911 call.

Defense Attorney George Filley lambasted Daniel on the stand last week after he discovered those other 911 tapes were now lost, having never made it to the District Attorney's office for review.

Ultimately, Duncan said, he tried to stay out of Marks' marital situation, which his wife told him was wrought with abuse.

He told jurors that if put in the same situation today, he'd pull the trigger again.

"They basically said, 'You have to look out for yourself out here,'" said Duncan, an oil-field operations supervisor.

Jurors will hear closing arguments at 8:30 a.m. Tuesday before beginning to deliberate. Judge Robert C. Cheshire is presiding.